To enable sharing of derived files,
use the CacheDir function
in any SConscript file:

CacheDir('/usr/local/build_cache')

Note that the directory you specify must already exist
and be readable and writable by all developers
who will be sharing derived files.
It should also be in some central location
that all builds will be able to access.
In environments where developers are using separate systems
(like individual workstations) for builds,
this directory would typically be
on a shared or NFS-mounted file system.

Here's what happens:
When a build has a CacheDir specified,
every time a file is built,
it is stored in the shared cache directory
along with its MD5 build signature.
[1]
On subsequent builds,
before an action is invoked to build a file,
SCons will check the shared cache directory
to see if a file with the exact same build
signature already exists.
If so, the derived file will not be built locally,
but will be copied into the local build directory
from the shared cache directory,
like so: